Data Validity Requirements For Ahrs Calibration Procedures; Configuration Mode Gsu Page Status Boxes - Garmin GDU 370 Installation Manual

For each Calibration Procedure, Table 8-2 lists the LRU's that require valid calibration data.
Table 8-2. Data Validity Requirements for AHRS Calibration Procedures
AHRS Calibration Procedure
Pitch/Roll Offset
Magnetic Calibration
Heading Offset
Engine Run-Up
Magnetometer Interference Test
Mounting Orientation Identification
Table 8-3 lists the type of valid calibration data required to be output by each LRU for the Calibration
Procedures listed in Table 8-2.
Table 8-3. Configuration Mode GSU Page Status Boxes
Status Box
GPS 3D or 3D Differential GPS solution available
True Airspeed (TAS) available. NOTE: A valid outside air temperature
Air Data
(OAT) measurement is required for TAS to be valid.
Magnetometer Measurement of local 3D magnetic field available
The GSU Page status boxes referred to in Table 8-3 are shown in the following figure.
If removal and replacement of a GMU 44 unit is required after post-installation calibration has been
completed, the GMU 44 mounting rack must not be moved. If the mounting screws that secure the
GSU 73 unit or the GMU 44 mounting rack are loosened for any reason, a new post-installation
calibration procedure, A, B, C and E (plus D if required initially) must be carried out before the aircraft
can be returned to service.
Any GMU 44 removal and replacement requires repeating the magnetometer calibration, and if
applicable, the heading offset compensation.
The addition, removal or modification of components that are ferrous, or otherwise magnetic, within 10.0
feet of the GMU 44 magnetometer location after the magnetometer interference test or magnetometer
calibration procedure were completed requires a repeat of both procedures.
Furthermore, electrical changes to the installation that affect components within 10.0 feet of the GMU 44
magnetometer after the magnetometer calibration and magnetometer interference procedures were
completed will require a repeat of the magnetometer interference test. If new magnetic interference is
detected, it must be resolved and then the magnetometer calibration procedure must be repeated. Wiring
or grounding changes associated with a device located in the same wing as the GMU 44 is a good
example of such a change.
G3X Installation Manual – Post Installation Checkout and Calibration Procedures
190-01115-01
Valid Status Required
GPS or Air Data
GPS or Magnetometer
GPS or Air Data.
Magnetometer always required.
GPS or Air Data
GPS or Air Data.
Magnetometer always required.
None
Valid Status
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Revision A